duenner



(No Model.) 3 Sheets-Sheet 1.

H. DUENNER. GOMMUTATOR FOR ELECTRIC MOTORS.

No. 449,774. Patented Apr. 7,1891.

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WITNESSES- a! Um/5mm: R 7Q @M '7 W (No Model.) 3 Sheets-Sheet 2.

H. DUENNER.

GOMMUTATOR FOR ELEOTRIG MOTORS.

No. 449,774. Patented Apr. '7, 1891. J; w

(No Model.) 3 Sheets-Sheet 3.

H. DUE R. GOMMUTATOR FOR EL 0 RIG MOTORS.

No, 449,774. Patented Apr. 7, 1891.

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illllllllliillli WI TNESSES xg INVEN FUR- UNITED STATES HENRY DUENNER, OF BOS"ON, MASS PATENT OEEIcE.

AOIIUSETTS, IISSIGNOR 0F ONE-HALF TO FREDERICK BLEILER, OF SAME PLACE.

ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 449,774, dated April *7, 1891.

Application filed October 16, 1890. Serial No. 368,252. (No model.)

To all 1071 0712 it may concern.-

Be it known that I, HENRY DUENNER, residing in Boston, in the county of Suffolk and State of Massachusetts, a subject of William, Emperor of Germany, have invented certain new and usefullmprovements in Oommutators for Electric Motors, of which the following is the specification.

It is well known that the brushes which are applied to the periphery of the commutatorcylinder require to be shifted endwise of the cylinder from time to time in orderto prevent the cylinder from wearing in circumferential grooves. This is usually done by loosening the nuts which hold the brushes to the spindle on which they are mounted and moving them endwise of the spindle and then fastening the nuts in a new place.

My improvement consists in mounting the brushes upon a spindle which is movable longitudinally and applying thereto crosshead slides and an adjusting-screw so that by a single turn of the screw the brushes may be adjusted longitudinally. This makes it much more convenient, and is economical of time.

In the drawings, Figure l is a plan of the improved apparatus as I have arranged it. Fig. 2 is a longitudinal section through the center of one of the brush-carrying spindles. Fig. 3 is a detail, partly in plan and partly in elevation, of a portion of the improved apparatus. The last two figures are on a larger scale than the scale of Fig. 1.

In the drawings, A indicates the commutator. The armature to which this commutator is attached and from which it derives its electricity is not shown.

B is the frame, which carries the brushspindles, and which supports them in their relation to the commutator.

G is an insulating-collar, which insulates the commutator from the frame. This collar has a neck which enters the frame and surrounds the commutator-shaft. This neck being concealed within the box'is not represented in the drawings, and F is a spindle or shaft forming part of the axis of the commutator.

O are the brushes formed, as usual, out of strips of metal. They are mounted, as shown in Fig. 2, in the blocks H, and are adjustable to and from the commutator on loosening the setscrews Q, and, when adjusted, these screws may be tightened again. These blocks II are mounted on a spindle D, which is at present usually fixed to the frame B. A usual way of applying these blocks H is shown in Fig. 3, where they are spaced from each other and allowed a little elasticity from the fact that they are fastened to the shaft D by a collar which has a gland something like the gland of a stuffing-box, which enters into a cavity in the box II and there compresses a spring contained in the same cavity. These oollars are fastened to the shaft by means of set-screws I. (Shown in the drawings, Fig. 3.) In the device which I have contrived this spindle passes through the frame B, and is not attached to said frame, but fits in it, so that it may be slid in and out, as desired. The handle P may be arranged to clamp this shaft in position when it has been set, if de sired, or a setscrew S may be employed for that purpose. I have added parts to the ordr nary construction for each set of brushes.

A pair of ways L, (shown in plan in Fig. l and in section in Fig. 2,) which ways at their outer end are united by a perforated yoke T, as shown in Fig. 2, project from the frame. These ways are formed so that an insulating cross-head or slide may be moved freely in them longitudinally of the ways. To this cross-head (marked K) is attached the spindle D, which is in condnoting-connection with the binding-post E, from which the conducting-wires are laid. The ways L are insulated from. the frame B. There is no conducting relation between the spindle D and the ways nor between the spindle D and the adjustingscrew. The insulating cross-head is shown in Fig. 2 as composed verylargely of insulating material and in Fig. 3 as composed of insulating material with a conductor embedded in it leading to the binding-post E; but it is obvious that it is not requisite to make the cross-head entirely of insulating material. Insulating material, must, however, be interposed between the spindleD andthe'adj ustinging screw m, and also between the adj ustingscrew m and the conductor, which leads from the spindle D to the binding-post E. There is mounted in the yoke T at the end of the ways an adjusting-screw m, which has a collar n and a shouldered milled head 0 for laying hold of it. This adj Listing-screw m lays hold of the cross-head and moves it and the spindle attached to it to and fro longitudinally of the ways.

It is obvious that any form of insulation that shall insulate the spindle D from the milled head 0 will practically suffice for the work of this apparatus, althoughitwould 11ndoubtedly be better to have the ways insulated from the spindle D, and also the adj usting-screw an insulated from the spindle D by suitable blocks of insulating material.

I claim as my invention and desire to secure by Letters Patent of the United States 1. The combination, in a commutator for dynamo-electric machines, of the brushes 0 the adjusting-screw, and .in conducting relao tions with the spindleD, substantially as and for the purposes described.

' HENRY DUENNER. Witnesses:

F. F. RAYMOND, 2d, J. M. DOLAN. 

